RESUMO
Objective: The purpose of this study was to evaluate the use of SPECT-CT for the determination of the anatomical locations of the cervical 131Iodine uptake areas during 131Iodine-whole body (131I-WB) scans. Methods: One hundred fifty-four patients who had undergone total thyroidectomyfor differentiated thyroid carcinoma (DTC) and had 131I-WB scan with cervical uptake images were studied with SPECT-CT, from March 2003 to October 2006. Results: From the 154patients included, 124 were women (80.5%) and the mean age of 46.09 ± 14.77 years. 131I-WB was performed 1-2 months after surgery in 137 patients (89.0%). The percentage of cervical uptake found varied between 0.1 and 15.0% and its mean was 1.42 ± 2.05%. Using SPECT-CT, 223 foci of cervical 131Iodine uptake (CIU) were identified in 154 patients. CIU foci were localized to the thyroid bed in 17 patients, while 29 patients presented with CIU in the thyroid bed and the extra thyroid tissue and in both the thyroid bed and extra thyroid tissues in another 29 patients. Inthe remaining 108 subjects, the CIU were located outside of the thyroid bed, of which the most common locations were the sternothyroid muscle and the thyroid cartilage. Conclusions: The useof SPECT-CT demonstrated significant diversity in the anatomical locations of CIU foci observed during 131I-WB scans after thyroidectomy for DTC